Cooler



FIG. 1 is a front perspective view of a cooler showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a front view thereof, the rear view being a mirror image thereof;

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a top perspective view thereof.

The broken lines shown in the drawings depict portions of the cooler that form no part of the claimed design. 

The ornamental design for a cooler, as shown and described. 